Last night Ofgem, the energy regulator, was accused of “illegal discrimination” against outlying communities by proposing electricity transmission charges for island wind farms that are up to seven times higher than for mainland wind generators.

The proposals could also sink Alex Salmond’s dreams of turning the Pentland Firth into the “Saudi Arabia” of wave and tidal energy.

The plans emerged yesterday after years of battling by renewable generators and the Scottish government to get the